Auditory brainstem potentials: comments on their use during infant development.

Abstract

Journal of Clinical Neur0ph_vsioI0g_\' l(3):33l—334, Raven Press. New York © l984 American Elcctrocncephalographic Society Auditory Brainstem Potentials: Comments on Their Use During Infant Development* A. Starr Department of Neurology. University of California Irvine, Irvine, California The review article by Salamy (1984) provides a perspective on the significance of auditory brainstem potentials in the newborn and developing infant with particular em- phasis on their use in quantifying and predicting development disorders. Dr. Salamy's methods of analysis involve measuring the latencies and amplitudes ofthe components ofthe auditory brainstem potentials during maturation and noting the effects ofchanges in certain stimulus parameters, such as rate. With these measures, Dr. Salamy believes that it is possible to distinguish and differentiate the group ofchildren at risk for hearing and neurological disorders from those who will develop normally. Ifthis premise were true, it would be a major contribution to the care ofthe newborn using the relatively sim- ple and noninvasive technique of auditory evoked potentials. However, I am not as optimistic as Dr. Salamy that the proposed measures of audi- tory brainstem potentials can provide the information for accurate prediction of the subsequent outcome of infants because of several limitations that Dr. Salamy himself considers. First, the methods of recording have limitations. Dr. Salamy has selected from the auditory brainstem potentials three principal waves from which he makes measure- ments, i.e., waves 1, III, and V. These components are elicited in a paradigm in which binaural stimulation is used and in which the recording is between the vertex and one of the mastoids or earlobes. Binaural stimulation assumes that the functioning of each cochlea is intact and that the central auditory pathways are symmetrically active. Chil- dren with altered unilateral central brainstem or cochlear function might be underesti— mated because stimulation of the unaffected ear using binaural signals would elicit normal components. Furthermore. since both recording sites are “active,” their differ- ential recording produces a mixture that may not reflect lateralized differences in the brainstem. Interpretation of auditory brainstem potentials would be simpler if the re- cordings were between the vertex and a noncephalic reference. I would prefer that monaural stimulation also be employed as a screen ofunilateral cochlear and brainstem disorders. ‘This review is complementary to that of A. Salamy.J Clin Neuroph_vsi0I l984:1:293—329. Address correspondence and reprint requests to Dr. Starr at Depanment of Neurology. University ofCal— ifornia Irvine. Irvine. California 92713. 331